The largest investigation of police corruption in Canadian history extended far beyond six Toronto officers charged this month, according to court documents unsealed Monday.

RCMP Chief Supt. John Neily, head of the probe into the allegations against the officers, said in affidavits that "evidence of criminal activity exists against 17 members" of the force, and that 12 were involved in "serious criminal activity."

Over a period of two years, investigators probing the Toronto drug squad filed seven affidavits.

Six officers were arrested this month on charges including theft, assault, perjury and obstruction of justice.

The court documents were released after a two-year access battle launched by the CBC and the Globe and Mail.

The affidavits allege that some police officers made up informants, stole hundreds of thousands of dollars and were willing to help launder money.

The documents also reveal that investigators found evidence of officers pretending to get tips from fake informants, then using the fabricated information to get search warrants.

According to the documents, the officers then stole hundreds of thousands of dollars, often by getting a safety deposit box key and helping themselves to money, jewelry, drugs and guns.

Investigators also pulled a "sting" operation on one police officer, who eagerly agreed to assist in a money-laundering scheme, according to one of the affidavits.

The search of another officer's home turned up illegal knives and a gun.

Documents also show that forensic accountants found that some of the officers under investigation had money and assets that appeared suspicious on a police officer's salary.